Methamphetamine (MA) is one of the most commonly used illicit drugs worldwide and is a major risk factor for the transmission of HIV infection. The neurotoxic effects of comorbid MA dependence and HIV infection (MA/HIV) preferentially impact the frontostriatal regions of the brain leading to increased prevalence of HIV-associated neurocognitive disorders (HAND) that affect up to 60% of the population, particularly disrupting higher-order executive functions (e.g., problem-solving abilities). In both HIV and MA, executive dysfunction is associated with dependence in instrumental activities of daily living (IADLs; e.g., medication or financial management). Despite the high risk for and economic burden of HAND-related disability (e.g., unemployment), there are currently no empirically validated techniques to treat HAND among MA users. One cognitive rehabilitation technique that has been effective for improving IADL functioning in other populations with executive dysfunction (e.g., traumatic brain injury) is metacognitive training. Metacognition involves the capacity for introspection including accurate perception and assessment of one's everyday performance and its consequences. Metacognition is commonly impaired following brain injury to the prefrontal systems and is associated with integrity of executive functions; in fact, up to 50% of HIV individuals show poor insight into their cognitive abilities, which is directly associated with poorer IADL outcomes in these individuals. Impaired metacognition may therefore represent an important mechanism by which executive dysfunction impacts successful IADL abilities in individuals with MA/HIV. Metacognitive training thus represents a potentially powerful technique to improve IADL functioning in MA/HIV. Metacognitive training is a cognitive rehabilitation technique that teaches individuals to self-regulate and monitor their thoughts and actions in order to gain control over their learning and behaviors. The proposed dissertation project aims to evaluate the efficacy of a brief metacognitive training module for neurocognitive rehabilitation in MA/HIV individuals with executive dysfunction. Due to the current absence of such techniques in this population, results from this study will inform future development of novel behavioral interventions to improve HAND among MA users. Through the implementation of this research project and the comprehensive training plan outlined in this F31 proposal including close interaction with expert mentors in a successful and collaborative research infrastructure (i.e., HIV Neurobehavioral Research Program), the applicant will enhance her scientific knowledge, research design techniques, and ability to further contribute to the fields of IADL functioning and neurocognitive rehabilitation in neuroAIDS and addictions. The opportunities afforded via this F31 mechanism will significantly contribute to the applicant's intermediate goal of attaining a K23 award focused on the development of empirically-based neurorehabilitation techniques and her long-term goal of becoming an independent neurorehabilitation scientist dedicated to improving the lives of persons living with substance use disorders and HIV infection.